- The estate of James Scott Molloy, assignee of Thomas O'Brien, at Fairfield, barony of Clonmacnowen, county Galway and Kilmore, barony of Athlone, county Roscommon, was offered for sale in the Encumbered Estates court in June and December 1850. The Freeman's Journal reported in February 1851 that they were purchased by George and Horatio Lawder.
- The Plunketts were a Catholic family residing at Mountplunkett from the 18th century. Christopher George Plunkett was a magistrate for county Roscommon in 1834. John Hubert Plunkett (1802-1867) became Attorney General of New South Wales, Australia. Many of his kinsmen followed him to Australia. The Mountplunkett demense was in the possession of Richard Stuart Crotty by 1850. It was leased to Patrick Grehan from 1847 for 14 years. Grehan appears to have bought Crotty's interest.
- Patrick Grehan had a lease of the Mountplunkett estate, parish of Killinvoy, barony of Athlone, county Roscommon, from 1847 and appears to have bought Crotty's interest in the property in 1851. In the 1850s Patrick Grehan held lands in the parishes of Killinvoy and St Johns, barony of Athlone, county Roscommon. In January 1870 the estate of Patrick Grehan amounting to 2,745 acres in the baronies of Athlone, Ballintober, Ballymoe and Castlerea was advertised for sale. The Mountplunkett estate and the part of South Park Demesne in the barony of Castlereagh were readvertised in May 1870. The Irish Times reported that these lots were sold to Rev. W. West and Owen O'Connor.
- The Mountplunkett demense was in the possession of Richard Stuart Crotty by 1850. It was leased to Patrick Grehan from 1847 for 14 years. In February 1851 John Scott Molloy, assignee of Richard S. Crotty, advertised for sale Mountplunkett and the lands of Drumlish, barony of Roscommon. On the first occasion the sale was adjourned due to insufficient bidding. Patrick Grehan appears to have bought Crotty's interest.